Is the amount of JRPG's on the DS that much?
Well...I guess they figure the graphics are sort of along the lines of a mutant PS1/N64 so that alone makes it easy to make games, also the amount of people who own a DS regardless of model is the best selling gaming device/console this gen.
Square Enix... = Greed Enix...
Then again i guess they have to do this for a back up just in case Final Fantasy XIII Flops lol.